A copper clad laminate and a method to manufacture the same are provided. In one general aspect, a copper clad laminate include a first copper clad layer on a first surface of an insulating layer, and a second copper clad layer on a second surface of the insulating layer. The second copper clad layer includes polymer resin layer, a second copper layer, and a carrier foil layer.

The present invention provides a surface treated copper foil in which a dropping of the roughening particles from a roughening treatment layer on the surface of the copper foil is suppressed and an occurrence of wrinkles or stripes when bonding with an insulating substrate is suppressed. The surface of the roughening treatment layer satisfies one or more of the following: a roughness Ra is 0.08 to 0.20 m, a roughness Rz is 1.00 to 2.00 m, a roughness Sq is 0.16 to 0.30 m, a roughness Ssk is 0.6 to 0.35, a roughness Sa is 0.12 to 0.23 m, a roughness Sz is 2.20 to 3.50 m, a roughness Sku is 3.75 to 4.50, and a roughness Spk is 0.13 to 0.27 m, a glossiness of a TD of the surface of the side of the roughening treatment layer of the surface treated copper foil is 70% or less.

Provided is a surface-treated copper foil excellent in laser processability. The surface-treated copper foil includes a roughened surface formed by subjecting a surface to a roughening treatment, in which when measured using a three-dimensional roughness meter, the roughened surface has a surface skewness Ssk within a range of from 0.300 to less than 0 and an arithmetic mean summit curvature Ssc within a range of from 0.0220 nm.sup.1 to less than 0.0300 nm.sup.1.

A printed circuit board includes an insulating body, a wiring structure at least disposed on the insulating body; and a shielding portion including a conductive via disposed around the wiring structure of the insulating body. The conductive via includes first and second metal layers having different degrees of magnetic permeability.

A resin film according to one aspect of the present invention is a resin film having polyimide as a main component, the resin film including a modified layer formed in a depth direction from at least one side of the resin film; and a non-modified layer other than the modified layer, wherein a ring-opening rate of an imide ring of the polyimide in the modified layer is higher than a ring-opening rate of an imide ring of the polyimide in the non-modified layer, and an average thickness of the modified layer from the one side of the resin film is greater than or equal to 10 nm and less than or equal to 500 nm.

An electromagnetic wave shielding sheet according to the disclosure is configured by a protection layer, a metal layer, and a conductive adhesive layer. The metal layer has a plurality of openings, and an aperture ratio of the opening is 0.1%-20%. In addition, a tensile breaking strength of the electromagnetic wave shielding sheet is 10 N/20 mm-80 N/20 mm.

A resin film according to one aspect of the present invention is a resin film having polyimide as a main component, the resin film including a modified layer formed in a depth direction from at least one side of the resin film; and a non-modified layer other than the modified layer, wherein a ring-opening rate of an imide ring of the polyimide in the modified layer is higher than a ring-opening rate of an imide ring of the polyimide in the non-modified layer, and an average thickness of the modified layer from the one side of the resin film is greater than or equal to 10 nm and less than or equal to 500 nm.

An electromagnetic wave shield film in which peeling off between a metal thin film and an adhesive layer is prevented and a printed wiring board employing the electromagnetic wave shield are provided. An electromagnetic wave shield film is formed by laminating at least a metal thin film and an adhesive layer in order, and the water vapor permeability of the electromagnetic wave shield film according to JISK7129 is 0.5 g/m.sup.2 per 24 hours or higher at a temperature of 80 degrees centigrade, a moisture of 95% RH, and a pressure difference of 1 atm.

An electromagnetic wave shield film in which peeling off between a metal thin film and an adhesive layer is prevented and a printed wiring board employing the electromagnetic wave shield are provided. An electromagnetic wave shield film is formed by laminating at least a metal thin film and an adhesive layer in order, and the water vapor permeability of the electromagnetic wave shield film according to JISK7129 is 0.5 g/m.sup.2 per 24 hours or higher at a temperature of 80 degrees centigrade, a moisture of 95% RH, and a pressure difference of 1 atm.

An electromagnetic wave shield film in which peeling off between a metal thin film and an adhesive layer is prevented and a printed wiring board employing the electromagnetic wave shield are provided. An electromagnetic wave shield film is formed by laminating at least a metal thin film and an adhesive layer in order, and the water vapor permeability of the electromagnetic wave shield film according to JISK7129 is 0.5 g/m.sup.2 per 24 hours or higher at a temperature of 80 degrees centigrade, a moisture of 95% RH, and a pressure difference of 1 atm.